Production of fibers from minerals and like materials



1943- G. VON PAZSICZKY ET AL 2,331,944

PRODUCTION OF FIBERS FROM MINERALS AND LIKE'MATERIALS Filed Feb. 3, 1959 HMLMUTH STEINGRAEBER mvsumus mew ArrbnnaY Patented Oct. 19, 1943 PRODUCTION OF FIBERS FROM AND LIKE MATERIALS MINERALS Gedeon von Pazsiczky, Hamburg-Wandsbek, and

Hellmuth Steingraebe vested in the r, Dusseldorf, Germany; Alien Property Custodian Application February 3, 1939, Serial No. 254,378 In Germany February 4, 1938 9 Claims.

Artificial mineral fibers, such as glass fibers, slag wool and the like, have a smooth surface. Due to this smoothness, treating and working of the said fibers into slivers, rovings, yarns, woven and knitted fabrics. etc., on the usual textile machines is difilcult. Ifhe smooth artificial fibers also lack satisfactory adherence in certain products made from them. They are also more diificult to felt and have a somewhat harsher feel than natural fibers.

It is one of the objects of our invention to devise a method of producing fibers with a rough surface from minerals and like materials, and more particularly from glass, which consists in roughening the surface of the fibers preferably as they are being formed, that is to say while the fibers are still hot and viscous.

According to this invention, roughening of the fibers may be efiected by eliminating through chemica agents constituents from the surface of the fibers'while being formed.

In the first case, acidic constituents, such as silicic acid, may be eliminatedfrom the surface of the fibers by subjecting the latter to the action of substances, such as for instance hydrofluoric acid, phosphoric acid, or other acids. The roughening of the fibers may also be obtained by eliminating alkaline constituents.

For instance, the fibers while being formed are treated with vapours, gases or liquids adapted to eliminate acidic constituents, or alkalis, alkaline earths or metal oxides'from the surface of the fibers.

Some modes of carrying the invention into effect will now be described in detail with reference to the accompanying drawing.

In the drawing:

Fig. 1 is a diagrammatic section of a device -for producing glass fibers having a roughened surface.

Fig. 2 is a plan view, greatly magnified, of a roughened glass fiber produced in accordance with the invention.

Fig. 3 is a diagrammatic section of another form of device for producing roughened fibers.

Referring first to Fig. 1, the numeral I denotes a melting receptacle holding a supply 2 of molten glass, siliceous slag or other material from which fibers are to be formed. The receptacle has in its bottom an orifice or a series of orifices 3 through which to deliver streams of molten material. These streams are subjected to the action of a drawing force attenuating the streams into fine filaments or fibers 4. According to Fig. 1, the drawing is effected by meansof gaseous blasts, such as high-pressure steam, which is supplied to an annular blowing nozzle 5 and issued fromthe latter in the direction of flow of the mass streams and more or less inclined towards the same. This mode of producing inorganic fibrous material is related to that disclosed in the Slayter and Thomas U. S. Patent No. 2,133,236.

For the purpose of the present invention, the gaseous blasts contain an amount of hydrofluoric acid or another suitable acid sufficient to etch the fibers by eliminating from their surfacessmall quantities of silicic acid, thereby roughening the surface. Care has to be taken that the corrosive action of the acid does not penetrate too much into the interior of the fibers and does not afiect the mechanical properties of the fibers.

The fibers 4 upon being formed and treated as described are subjected to a thermal treatment, for instance in a heated chamber 6, for avoiding condensation of the silicic-hydrofiuoric acid on the surface of the fibers as well as for carrying off the silicic-hydrofluoric acid in gaseous form and for drying the fibers.

If necessary or desired, the fibers may be subjected to a repeated treatment with fluids capable of etching them and increasing the roughness already obtained.

Fig. 2 illustrates the surface structure of a glass fiber produced according to the invention. The surface shows tiny scale-like cavities or irregularities so that under the microscope the fibers have the appearance of animal wool.

When producing endless glass filaments by mechanical drawing, the filaments while being .formed are preferably passed through a chamber filled with a gaseous medium containing the necessary reacting agents.

With the form of device illustrated by Fig. 3, the molten material 2, such as glass, exudes through the orifice 3 in the form of a cone 1 and is drawn into an endless filament 8 of desired fineness, in a manner known in the art, by mechanical-means such as a rotating drum (not shown). According to the invention, there is arranged below the melting receptacle l a treating chamber 9 into which projects a pipe I 0 through which vapours of stannic chloride are blown into the chamber and caused to strike against the liquid molten glass cone I where they eliminate from the surface of the cone, as-

surface of the filament tiny leaves or scales. The

fibers obtained also possess a favorable roughness rendering them suitable for being worked into textile products.

Instead of stannic chloride there may be used titanic chloride or other chlorides, hydrochloric acid or other volatile agents adapted to eliminate from the surface of the glass filaments alkaline constituents, such as alkalis, alkaline earths or metal oxides, by the formation for example gases may also be led as counter-currents relative to the direction in which the fibers are drawn.

In the operation of the device of Fig. 3 provision should be made for preventing the glass cone 1 from being too strongly cooled by the gas admitted through pipe I0. In this respect, the exuding glass cone may be exposed to an additional source of heat or the gases or vapours supplied are heated to a temperature sufliciently high to avoid interruption of the spinning or drawing operation.

Having thus described our invention, what we claim as new and desire to secure by Letters Patent is:

1. The method of producing filaments with a rough surface from glass, which comprises melting the glass, flowing a stream of the molten glass and applying a drawing force to said stream so as to attenuate it into fine filaments, and eliminating acidic constituents from the glass at the surface of the stream while the glass of the stream is hot and plastic and is being attenuated, thereby providing a roughened surface on the finished filaments.

2. The method of producing glass fibers with a rough surface which comprises providing a supply body of molten glass, flowing the molten glass from said supply body in the form of a stream, applying an attenuating force to the stream of molten glass so as to draw it out into fine filaments, and subjecting the stream while the glass thereof is hot and plastic to the action of hydrofluoric acid, thereby eliminating silicic acid constituents from the glass of the stream at the surface thereof, whereby a roughened surface is provided on the finished filaments.

3. The method of producing glass fibers with a rough surface which comprises providing a supply body of molten glass, flowing the molten glass from said supply body in the form of a, stream, applying an attenuating force to the stream of molten glass so as to draw it out into fine filaments, and subjecting the stream while the glass thereof is hot and plastic to the action of phosphoric acid, thereby eliminating acidic constituents from the glass at the surface of the stream, whereby a roughened surface is provided on the finished filaments.

4. The method of producing glass fibers with a rough surface which comprises providing a supply of molten glass, flowing molten glass from said supply in the form of a stream, directing gaseous blasts onto said stream to applya drawing force to the stream and attenuate the stream fluoric acid in vapourous form to react with the plastic glass of the stream, thereby providing roughened surfaces on the finished filaments.

5,. The method of producing glass fibers suitable for textile purposes which comprises melting inorganic material to form a supply of molten glass, flowing a stream of molten glass from said supply and applying a drawing force to the stream to attenuate the same into a filament, simultaneously cooling said glass 'as it is being at-- tenuated to cause it to solidify, and providing a roughened surface on said filament by applying hydrofluoric acid to the surface of the glass as it is being attenuated and prior to solidification into a filament.

' 6. The method of producing glass fibers suit able for textile purposes which comprises melting inorganic material to form a supply of molten glass, flowing a stream of molten glass from said supply and applying a drawing force to the stream to attenuate the same into a filament, simultaneously cooling said glass as it is being attenuated to cause it to solidify, providing a roughened surface on said filament by applying to the surface of the glass while it is being attenuated and prior to solidification into a filament, vapors of hydrofluoric acid to chemically react with the surface of said glass, and maintaining said vapours in vapour form to prevent condensation thereof onto said filament.

"I. The method of producing glass fibers having roughened surfaces which comprises melting inorganic material to form a supply of molten glass, flowing molten glass from said supply in the form of streams and applying a drawing force to attenuate the streams into filaments, and blowing into contact with the glass streams during attenuation and prior to solidification thereof, vapours of an acid selected from the group consisting of hydrofluoric and phosphoric to react with the plastic glass and eliminate constituents from the glass streams at the surfaces thereof.

8. The method of producing glass fibers having roughened surfaces which comprises melting inorganic material to form a supply of molten glass, flowing a stream of said molten glass and applying a drawing force to attenuate the same into a filament, and applying to the surface of the hot, plastic glass stream while being attenuated and before solidification into a filament, vapours of hydrofluoric acid adapted to chemically react with the plastic glass to eliminate constituents of the glass from the glass stream at th surface thereof, thereby providing roughened surfaces on the finished filament.

9. The method of producing glass fibers having roughened surfaces which comprises melting inorganic material to form a supply of molten glass, flowing a stream of said molten glass and applying a drawing force to attenuate the same into a filament, and applying to the surface of the hot, plastic glass stream while being attenuated and before solidification into a filament, vapours of phosphoric acid to react with the plastic glass to eliminate constituents of the glass from the glass stream at the surface thereof, thereby providing roughened surfaces on the finished filament.

GEDEON VON PAZSICZKY. HELIMUTH STEINGRAEBER. 

